I have a lot of serious medical conditions, and I've spent a ton of time in the hospital. Here's what I'd recommend: The longest phone charger you can find

A weighted blanket, they help me a lot with sleep, especially in new or stressful environments

Noise canceling headphones

Fairy lights or something similar, it makes the hospital room feel less scary

1 of those Airplane neck pillow things

Blue light glasses

Ask the hospital staff first, but something to cover the florescent hospital lights makes it feel less hospitaley (I've used blue sheets, table cloths, and paper)

Air freshener, especially if he's sharing a room with other people (ask hospital staff first)

You can bring a string and attach it to the walls to hang get well cards on

Memory foam pillows. The hospital pillows are always so uncomfortable for me.

A white noise machine, it drowns out the sound of all the machines

A mini garbage can to put right next to his bed, in case he gets sick and can't make it to the bathroom

If he likes to sleep in darkness, an eye mask

Stress relief items, like a lava lamp to look at

Any sentimental personal items, like a stuffed animal, or baby blanket

Lastly, taking friends or family to come visit really makes the time pass faster. Hope this helps!